This invention relates generally to an optical system and, more particularly, to an optical system for providing stationary images of rotating objects.
Heretofore, stroboscope type devices have been employed to measure rotational speed of a body. A typical stroboscope includes a pulsing light source which provides pulses of light at a controlled rate. These pulses of light illuminate the rotating body which preferably is shrouded by darkness except for the light from the pulsating source. When the rate of the light pulses is equal to the rotational speed of the body, the body appears to the observer to be stationary. However, due to the intermittent nature of the stroboscope light and the quality of the light, detail inspection of the rotating body by the observer is most difficult and, at best, the observer can merely ascertain that the pulse rate is the same as the rotational speed of the body and thereby determine the rotational speed of the body. It is most difficult for the observer to inspect in detail various parts, components or occurrences in the body during rotation by employing such a stroboscope device. For example, it is difficult for an observer to employ a stroboscope to observe a centrifuge in action so as to inspect the processes of separation, precipitation or other phenomenon which occurs during centrifuge. Inspection is difficult because of the intermittent nature of the stroboscope light and the quality of the light. Furthermore, illumination is limited to light that can presently be obtained within the state of the art with stroboscope devices. This does not include all of the visible spectrum, infrared, microwave and other bands of radiation.
U.S. Pat. No. 3,449,035 discloses an optical system which provides an observer with stationary images of rotating objects. The optical system disclosed in the patent alleviates many of the above described disadvantages inherent in stroboscope devices. However, the system exhibits other deficiencies such as cumbersome optical and mechanical arrangements, intricate production and assembly requirements and less than satisfactory image reproduction.
The object of this invention, therefore, is to provide an improved optical system for producing stationary images of rotating objects.